Highest degrees of host specificity even in the inundative biocontrol approach : response to Cripps et al.

Volume: 13Start Page: 41End Page: 4

Taxonomic note on Aculepeira lapponica (Arachnida: Araneae: Araneidae)

Caused by the similarity with the type species Aculepeira packardi and with A. ceropegia we confirm the combination Aculepeira lapponica for the arctic araneid Aranea lapponica Holm, 1945

Plant pathogens as biocontrol agents of Cirsium arvense : an overestimated approach?

Cirsium arvense is one of the worst weeds in agriculture. As herbicides are not very effective and not accepted by organic farming and special habitats, possible biocontrol agents have been investigated since many decades. In particular plant pathogens of C. arvense have received considerable interest and have been promoted as “mycoherbicides” or “bioherbicides”. A total of 10 fungi and one bacterium have been proposed and tested as biocontrol agents against C. arvense. A variety of experiments analysed the noxious influence of spores or other parts of living fungi or bacteria on plants while others used fungal or bacterial products, usually toxins. Also combinations of spores with herbicides and combinations of several pathogens were tested. All approaches turned out to be inappropriate with regard to target plant specificity, effectiveness and application possibilities. As yet, none of the tested species or substances has achieved marketability, despite two patents on the use of Septoria cirsii and Phomopsis cirsii. We conclude that the potential of pathogens for biocontrol of C. arvense has largely been overestimated

Distributed Holistic Clustering on Linked Data

Link discovery is an active field of research to support data integration in the Web of Data. Due to the huge size and number of available data sources, efficient and effective link discovery is a very challenging task. Common pairwise link discovery approaches do not scale to many sources with very large entity sets. We here propose a distributed holistic approach to link many data sources based on a clustering of entities that represent the same real-world object. Our clustering approach provides a compact and fused representation of entities, and can identify errors in existing links as well as many new links. We support a distributed execution of the clustering approach to achieve faster execution times and scalability for large real-world data sets. We provide a novel gold standard for multi-source clustering, and evaluate our methods with respect to effectiveness and efficiency for large data sets from the geographic and music domains

Kuschka V. (2004): Ackerbrachen als Chance für den Naturschutz? Struktur und Dynamik von Spinnenzönosen der Bodenoberfläche als Indikator der Habitatqualität

Buchbesprechun

Introduction, establishment rate, pathways and impact of spiders alien to Europe

A comprehensive analysis of spiders reported as alien for Europe over the last 200 years has yielded information for 184 spider species, which had been introduced at least once. The most common spider families are Theridiidae (27 species), Pholcidae (15), Salticidae (14), Sparassidae (14), Ctenidae (14), and Theraphosidae (13) but overall establishment rate was only 28 %. No ctenids or theraphosids established, and only one sparassid species, but many theridiids and pholcids. Most introduced species originated from South (34 %), Central (10 %) or North (12 %), America, Asia (19 %) and Africa (15 %). Only few of the South and Central American species could establish, while species from North America (36 %) and Asia (63 %) had much higher establishment rates. Over the last 200 years, introduction and establishment rates have been strongly increasing. Three pathways are responsible for the majority of introductions: fruit shipments (67 % of all cases), potted plants (16 %) and containers or packaging material (12 %). In contrast to fruit shipments, spiders introduced on plants or with containers have high establishment rates (65 and 47 %). Environmental impact of alien spiders can be expected on both insects (through predation) and spiders (through predation and competition), potentially leading to change of species composition and guild structure. Socio-economic impact includes reduction of marketability of horticultural products through excessive spinning activity which also may cause increased cleaning costs at facades and windows. Impact on human health may be caused by bites and subsequent need for medical treatments. For all these impact categories, however, only anecdotal evidence is given for alien spiders in Europe. This may change when spiders of medical importance such as the frequently introduced Latrodectus species will establish. Considering the current trends it is concluded that introduction and establishment rates of alien spiders will strongly increase in the next years unless preventive methods become more efficient

Expression of defensins in non-infected araneomorph spiders

Defensins are a major family of antimicrobial peptides found throughout the phylogenetic tree. From the spider species: Cupiennius salei, Phoneutria reidyi, Polybetes pythagoricus, Tegenaria atrica, and Meta menardi, defensins belonging to the ‘ancestral' class of invertebrate defensins were cloned and sequenced. The deduced amino acid sequences contain the characteristic six cysteines of this class of defensins and reveal precursors of 60 or 61 amino acid residues. The mature peptides consist of 37 amino acid residues, showing up to 70% identities with tick and scorpion defensins. In C. salei, defensin mRNA was found to be constitutively expressed in hemocytes, ovaries, subesophageal nerve mass, hepatopancreas, and muscle tissue. This is the first report presenting and comparing antimicrobial peptides belonging to the family of defensins from spider

Scalable Data Integration for Linked Data

Linked Data describes an extensive set of structured but heterogeneous datasources where entities are connected by formal semantic descriptions. In thevision of the Semantic Web, these semantic links are extended towards theWorld Wide Web to provide as much machine-readable data as possible forsearch queries. The resulting connections allow an automatic evaluation to findnew insights into the data. Identifying these semantic connections betweentwo data sources with automatic approaches is called link discovery. We derivecommon requirements and a generic link discovery workflow based on similaritiesbetween entity properties and associated properties of ontology concepts. Mostof the existing link discovery approaches disregard the fact that in times ofBig Data, an increasing volume of data sources poses new demands on linkdiscovery. In particular, the problem of complex and time-consuming linkdetermination escalates with an increasing number of intersecting data sources.To overcome the restriction of pairwise linking of entities, holistic clusteringapproaches are needed to link equivalent entities of multiple data sources toconstruct integrated knowledge bases. In this context, the focus on efficiencyand scalability is essential. For example, reusing existing links or backgroundinformation can help to avoid redundant calculations. However, when dealingwith multiple data sources, additional data quality problems must also be dealtwith. This dissertation addresses these comprehensive challenges by designingholistic linking and clustering approaches that enable reuse of existing links.Unlike previous systems, we execute the complete data integration workflowvia a distributed processing system. At first, the LinkLion portal will beintroduced to provide existing links for new applications. These links act asa basis for a physical data integration process to create a unified representationfor equivalent entities from many data sources. We then propose a holisticclustering approach to form consolidated clusters for same real-world entitiesfrom many different sources. At the same time, we exploit the semantic typeof entities to improve the quality of the result. The process identifies errorsin existing links and can find numerous additional links. Additionally, theentity clustering has to react to the high dynamics of the data. In particular,this requires scalable approaches for continuously growing data sources withmany entities as well as additional new sources. Previous entity clusteringapproaches are mostly static, focusing on the one-time linking and clustering ofentities from few sources. Therefore, we propose and evaluate new approaches for incremental entity clustering that supports the continuous addition of newentities and data sources. To cope with the ever-increasing number of LinkedData sources, efficient and scalable methods based on distributed processingsystems are required. Thus we propose distributed holistic approaches to linkmany data sources based on a clustering of entities that represent the samereal-world object. The implementation is realized on Apache Flink. In contrastto previous approaches, we utilize efficiency-enhancing optimizations for bothdistributed static and dynamic clustering. An extensive comparative evaluationof the proposed approaches with various distributed clustering strategies showshigh effectiveness for datasets from multiple domains as well as scalability on amulti-machine Apache Flink cluster

Antimicrobial and cytolytic peptides of venomous arthropods

As a response to invading microorganisms, the innate immune system of arthropods has evolved a complex arrangement of constitutive and inducible antimicrobial peptides that immediately destroy a large variety of pathogens. At the same time, venomous arthropods have developed an additional offensive system in their venom glands to subdue their prey items. In this complex venom system, several enzymes, low-molecular-mass compounds, neurotoxins, antimicrobial and cytolytic peptides interact together, resulting in extremely rapid immobilization and/or killing of prey or aggressors. This review provides an overview of antimicrobial peptides identified in the hemolymph of venomous arthropods, and especially of cytolytic peptides in their venom. For these peptides a dual role is proposed: acting as antimicrobials as well as increasing the potency of the venom by influencing excitable cell

Spider (Arachnida: Araneae) distribution across the timberline in the Swiss Central Alps (Alp Flix, Grisons) and three morphologically remarkable species

We collected 6251 adult epigeic spiders from the dwarf-shrub heath to subalpine coniferous forest on Alp Flix (CH, canton Grisons, 1950 m) between May 2005 and May 2006 using pitfall traps. Total species richness and activity density of all species decreased from the open land to the forest, although this pattern varied according to family. The distribution of the 102 species found indicates that the small area around a single tree at the timberline provides habitats for both open land and forest spider species as well as some possible timberline specialists. Five species were new to the canton Grisons: Centromerita bicolor, Centromerita concinna, Hilaira excisa, Meioneta alpica and Tallusia experta. Three species showed remarkable morphological characteristics and were analysed in more detail. We found males of Pelecopsis radicicola without the characteristic longitudinal depression on the raised carapace. It is shown that the males of Meioneta alpica have a considerably variable lamella characteristica, which is nevertheless distinct from the sister species Meioneta ressli. Because we found intermediate forms of the head region described for Metopobactrus prominulus and M. schenkeli, respectively, M. schenkeli is considered a syn. nov. of M. prominulus. This study shows that the known distribution and taxonomic status of various spider taxa in the Central Alps are still incomplete and further work on arthropods in remote areas should be strongly encouraged